Russia has strict abortion laws but Putin could just ban it entirely like many Eastern bloc countries did after WW2 and further encourage having children with money. It was not unheard of for people in Eastern Europe to receive flats by signing a government contract to have 2-3 children. Many people would still choose the coat hanger but numbers would rise eventually. This decoration (the successor of the old Soviet Mother Heroine) is already awarded to biological and adoptive parents of large families with a hefty 100 thousand RUB reward:
en.wikipedia.org